/*
 * Copyright 2002-2019 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.aop.support;

import org.aopalliance.aop.Advice;
import org.springframework.aop.ClassFilter;
import org.springframework.aop.DynamicIntroductionAdvice;
import org.springframework.aop.IntroductionAdvisor;
import org.springframework.aop.IntroductionInfo;
import org.springframework.core.Ordered;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;

import java.io.Serializable;
import java.util.LinkedHashSet;
import java.util.Set;

/**
 * Simple {@link org.springframework.aop.IntroductionAdvisor} implementation
 * that by default applies to any class.
 *
 * @author Rod Johnson
 * @author Juergen Hoeller
 * @since 11.11.2003
 */
@SuppressWarnings("serial")
public class DefaultIntroductionAdvisor implements IntroductionAdvisor, ClassFilter, Ordered, Serializable {

    private final Advice advice;

    private final Set<Class<?>> interfaces = new LinkedHashSet<>();

    private int order = Ordered.LOWEST_PRECEDENCE;


    /**
     * Create a DefaultIntroductionAdvisor for the given advice.
     *
     * @param advice the Advice to apply (may implement the
     *               {@link org.springframework.aop.IntroductionInfo} interface)
     * @see #addInterface
     */
    public DefaultIntroductionAdvisor(Advice advice) {
        this(advice, (advice instanceof IntroductionInfo ? (IntroductionInfo) advice : null));
    }

    /**
     * Create a DefaultIntroductionAdvisor for the given advice.
     *
     * @param advice           the Advice to apply
     * @param introductionInfo the IntroductionInfo that describes
     *                         the interface to introduce (may be {@code null})
     */
    public DefaultIntroductionAdvisor(Advice advice, @Nullable IntroductionInfo introductionInfo) {
        Assert.notNull(advice, "Advice must not be null");
        this.advice = advice;
        if (introductionInfo != null) {
            Class<?>[] introducedInterfaces = introductionInfo.getInterfaces();
            if (introducedInterfaces.length == 0) {
                throw new IllegalArgumentException("IntroductionAdviceSupport implements no interfaces");
            }
            for (Class<?> ifc : introducedInterfaces) {
                addInterface(ifc);
            }
        }
    }

    /**
     * Create a DefaultIntroductionAdvisor for the given advice.
     *
     * @param advice the Advice to apply
     * @param ifc    the interface to introduce
     */
    public DefaultIntroductionAdvisor(DynamicIntroductionAdvice advice, Class<?> ifc) {
        Assert.notNull(advice, "Advice must not be null");
        this.advice = advice;
        addInterface(ifc);
    }


    /**
     * Add the specified interface to the list of interfaces to introduce.
     *
     * @param ifc the interface to introduce
     */
    public void addInterface(Class<?> ifc) {
        Assert.notNull(ifc, "Interface must not be null");
        if (!ifc.isInterface()) {
            throw new IllegalArgumentException("Specified class [" + ifc.getName() + "] must be an interface");
        }
        this.interfaces.add(ifc);
    }

    @Override
    public Class<?>[] getInterfaces() {
        return ClassUtils.toClassArray(this.interfaces);
    }

    @Override
    public void validateInterfaces() throws IllegalArgumentException {
        for (Class<?> ifc : this.interfaces) {
            if (this.advice instanceof DynamicIntroductionAdvice &&
                    !((DynamicIntroductionAdvice) this.advice).implementsInterface(ifc)) {
                throw new IllegalArgumentException("DynamicIntroductionAdvice [" + this.advice + "] " +
                        "does not implement interface [" + ifc.getName() + "] specified for introduction");
            }
        }
    }

    @Override
    public int getOrder() {
        return this.order;
    }

    public void setOrder(int order) {
        this.order = order;
    }

    @Override
    public Advice getAdvice() {
        return this.advice;
    }

    @Override
    public boolean isPerInstance() {
        return true;
    }

    @Override
    public ClassFilter getClassFilter() {
        return this;
    }

    @Override
    public boolean matches(Class<?> clazz) {
        return true;
    }


    @Override
    public boolean equals(Object other) {
        if (this == other) {
            return true;
        }
        if (!(other instanceof DefaultIntroductionAdvisor)) {
            return false;
        }
        DefaultIntroductionAdvisor otherAdvisor = (DefaultIntroductionAdvisor) other;
        return (this.advice.equals(otherAdvisor.advice) && this.interfaces.equals(otherAdvisor.interfaces));
    }

    @Override
    public int hashCode() {
        return this.advice.hashCode() * 13 + this.interfaces.hashCode();
    }

    @Override
    public String toString() {
        return getClass().getName() + ": advice [" + this.advice + "]; interfaces " +
                ClassUtils.classNamesToString(this.interfaces);
    }

}
